KR102456472B1 - Strain wave gear device - Google Patents

Abstract

A wave gear device capable of reducing weight is disclosed. The wave gear device includes an input shaft, a wave generator coupled to the input shaft, and a wave generator having an elliptical cross-sectional shape, provided on an outer circumferential surface of the wave generator, a cylinder in which external teeth are formed on the outer circumferential surface of the front end and the rear end extends in the outward direction to form a boss An externally toothed gear having a shape, an internal toothed gear provided on an outer peripheral surface of the externally toothed gear and having internal teeth formed on an inner peripheral surface, a housing provided outside the internally toothed gear and coupled to the boss, and provided between the internally toothed gear and the housing an input bearing comprising: an inner ring of the input bearing integrally formed with the internal toothed gear, and an outer ring of the bearing integrally formed with the housing.

Description

Wave Gear Device {STRAIN WAVE GEAR DEVICE}

The following description relates to a wave gear arrangement.

A wave gear device is a type of reduction gear, a rigid ring-shaped internal toothed gear (circular spline), a flexible cylindrical external toothed gear (flex spline) provided on the inner circumferential surface of the internal toothed gear, and a high rigidity ellipse provided inside the externally toothed gear It includes a wave generator of the shape. In addition, the wave gear device is known as a cup type, a silk hat type, and a flat type depending on the shape of the body of the external gear.

In the wave gear device, the external gear is deformed into an elliptical shape by the wave generator, and meshes with the internal gear at both ends in the longitudinal direction thereof. And as the wave generator rotates, the meshing positions of both gears move in the circumferential direction, and relative rotation due to the dimensional difference between the two gears occurs along the circumferential direction. Here, one gear (for example, an internal gear) of both gears is fixed to a housing etc., and the reduced rotation based on a dimensional difference is output from the other gear which is not fixed.

On the other hand, the wave gear device includes an input shaft and an input bearing that supports rotation with respect to the input shaft. Crossed roller bearings are mainly used as input bearings. Conventionally, in order to reduce the weight of the wave gear device, improvements have been made to reduce the weight of the crossed roller bearing.

The above-mentioned background art is possessed or acquired by the inventor in the process of deriving the disclosure of the present application, and it cannot necessarily be said to be a known technology disclosed to the general public prior to the present application.

An object of the embodiment is to provide a wave gear device capable of reducing the weight of the input bearing and reducing the size of the housing in the wave gear device.

The problems to be solved in the embodiments are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

A wave gear device according to an embodiment will be described.

The wave gear device includes an input shaft, a wave generator coupled to the input shaft, and a wave generator having an elliptical cross-sectional shape, provided on an outer circumferential surface of the wave generator, a cylinder in which external teeth are formed on the outer circumferential surface of the front end and the rear end extends in the outward direction to form a boss An externally toothed gear having a shape, an internal toothed gear provided on an outer peripheral surface of the externally toothed gear and having internal teeth formed on an inner peripheral surface, a housing provided outside the internally toothed gear and coupled to the boss, and provided between the internally toothed gear and the housing an input bearing comprising: an inner ring of the input bearing integrally formed with the internal toothed gear, and an outer ring of the bearing integrally formed with the housing.

According to one side, the bearing may be a tapered roller bearing inclined with respect to the input shaft. A first inclined surface corresponding to the outer peripheral surface of the bearing is formed on the inner surface of the housing, and a second inclined surface corresponding to the outer peripheral surface of the bearing is formed on the outer surface of the internal gear, and the bearing includes the first inclined surface and the second It may be disposed between the inclined surfaces.

According to one side, the bearing may be an angular ball bearing. A first inclined surface of a predetermined angle is formed on an inner surface of the housing, a second inclined surface corresponding to the first inclined surface is formed on an outer surface of the internal gear, and the bearing is disposed between the first inclined surface and the second inclined surface can be

According to one side, the externally toothed gear includes a cylindrical body having an open front end, and a diaphragm in which the other end of the body extends outwardly and the boss is formed, and the internally toothed gear covers the body. can be formed to

According to embodiments, the size of the bearing may be reduced and the size of the housing may be reduced by integrally forming the inner ring of the bearing with the internal tooth gear and integrally forming the outer ring of the bearing with the housing.

Effects of the wave gear device according to the embodiment are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description below.

1 is a side cross-sectional view of a wave gear device according to an embodiment;
FIG. 2 is an enlarged view of an input bearing part of the wave gear device of FIG. 1 .

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. However, since various changes may be made to the embodiments, the scope of the patent application is not limited or limited by these embodiments. It should be understood that all modifications, equivalents and substitutes for the embodiments are included in the scope of the rights.

The terms used in the examples are used for the purpose of description only, and should not be construed as limiting. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present specification, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It is to be understood that this does not preclude the possibility of the presence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the embodiment belongs. Terms such as those defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application. does not

In addition, in the description with reference to the accompanying drawings, the same components are assigned the same reference numerals regardless of the reference numerals, and the overlapping description thereof will be omitted. In the description of the embodiment, if it is determined that a detailed description of a related known technology may unnecessarily obscure the gist of the embodiment, the detailed description thereof will be omitted.

In addition, in describing the components of the embodiment, terms such as first, second, A, B, (a), (b), etc. may be used. These terms are only for distinguishing the elements from other elements, and the essence, order, or order of the elements are not limited by the terms. When it is described that a component is “connected”, “coupled” or “connected” to another component, the component may be directly connected or connected to the other component, but between each component another component It will be understood that may also be "connected", "coupled" or "connected".

Components included in one embodiment and components having a common function will be described using the same names in other embodiments. Unless otherwise stated, descriptions described in one embodiment may be applied to other embodiments as well, and detailed descriptions within the overlapping range will be omitted.

Hereinafter, the wave gear device 100 will be described with reference to FIGS. 1 to 2 . For reference, FIG. 1 is a side cross-sectional view in the direction of the tooth line of the wave gear device 100 according to an embodiment, and FIG. 2 is an enlarged portion of the input bearing 150 in the wave gear device 100 of FIG. 1 . It is a drawing showing In addition, in the following description, directions of "up, down, front, back" will be described with reference to FIG. 1 .

Referring to the drawings, the wave gear device 100 includes an input shaft 10 , an internal gear 110 , an external gear 120 , a wave generator 130 , a housing 140 , and an input bearing 150 . consists of including.

The externally toothed gear 120 is provided on the same axis with the internally toothed gear 110 to engage the inner peripheral surface of the internally toothed gear 110 . Externally toothed gear 120 is deformed into an elliptical shape by the shape of the wave generator 130 as the wave generator 130 is fitted in the open front end, and the external tooth 122 is partially on the internal tooth 112 on its long axis. will be intertwined

The body 121 of the external gear 120 has a cylindrical shape with an open front end and has flexibility. An outer tooth 122 engaged with the inner tooth 112 is formed on the outer peripheral surface of the front end of the body 121 . For example, the external toothed gear 120 may be a spur gear in which the tooth line direction is parallel to the input shaft 10 direction.

The external gear 120 may be of a silk hat type in which the diaphragm 123 is formed radially outward from the rear end of the body 121 . The diaphragm 123 has a disk shape extending in a direction perpendicular to the axial direction of the body 121 . However, the shape of the external gear 120 is not limited by the drawings, and a cup type or a flat type may be used.

A plurality of boss portions 124 are formed along the circumference of the diaphragm 123 , and a plurality of through holes 124a are formed so that a fastening member (not shown) can pass through to be fastened to the housing 140 . In addition, the boss portion 124 is formed to have a greater thickness than the diaphragm 123 .

The wave generator 130 is provided coaxially with the externally toothed gear 120 so as to be fitted on the inner circumferential surface of the externally toothed gear 120 . The wave generator 130 is formed in an elliptical shape and includes a rigid plug 131 to which the input shaft 10 is coupled, and a bearing 132 provided between the plug 131 and the externally toothed gear 120 . The wave generator 130 deforms the external toothed gear 120 into an elliptical shape and causes the external tooth 122 to mesh with the internal tooth 112 on the major axis of the ellipse.

The internal gear 110 is formed to include a rigid body 111 formed in a circular ring shape, and internal teeth 112 formed on an inner circumferential surface of the body 111 . For example, the internal tooth gear 110 may be a spur gear in which a tooth trace direction is parallel to the input shaft 10 .

Here, the internal gear 110 may be formed so that the body 111 extends to the rear. That is, the body 111 of the internally toothed gear 110 extends to the diaphragm 123 and has a shape surrounding the externally toothed gear 120 , and serves as a housing.

According to the present embodiment, since the internal gear 110 also serves as a housing for accommodating the internal gear 110 , the wave gear device 100 and the housing 140 may be reduced in weight and the structure may be simplified.

The housing 140 is provided on the outside of the internally toothed gear 110 to accommodate the internally toothed gear 110 . In addition, one end of the housing 140 is coupled to the boss portion 124 of the externally toothed gear 120 by a plurality of fastening members (not shown).

Hereinafter, for convenience of description, the assembly of "the internal gear 110, the external gear 120, and the wave generator 130" is referred to as a "gear unit".

The housing 140 has a shape surrounding the outer side of the internal gear 110 to accommodate the gear unit, and supports the gear unit to be rotatable by the input shaft 10 . For example, the housing 140 may include a first housing member 141 provided at the front of the boss unit 124 and a second housing member 142 provided at the rear of the boss unit 124 .

For example, the second housing member 142 may have a shape covering the rear of the external gear 120 , and the input shaft 10 may be installed to pass through the center thereof. Also, in the second housing member 142 , a support bearing 143 may be provided between the input shaft 10 and the outer peripheral surface of the input shaft 10 so that the input shaft 10 is rotatable.

The first housing member 141 supports the gear unit to be relatively rotatable by the input bearing 150 .

The input bearing 150 is provided between the housing 140 (first housing member 141 ) and the internally toothed gear 110 so that the internally toothed gear 110 is rotatable with respect to the housing 140 . In the input bearing 150 , the inner ring is integrally formed with the internally toothed gear 110 , the outer ring is integrally formed with the housing 140 , and the bearing member 151 is provided between the internally toothed gear 110 and the housing 140 . do.

Here, the input bearing 150 may be a tapered roller bearing. And the internal gear 110 has a first inclined surface 111a that becomes the inner ring of the input bearing 150 is formed, and the housing 140 has a second inclined surface 141a that becomes the outer ring of the input bearing 150 is formed, A bearing member 151 is installed on the first and second inclined surfaces 111a and 141a.

The bearing member 151 has a truncated cone shape having a bottom surface having a predetermined diameter and a side surface made of a bus bar at a predetermined height and a predetermined angle with respect to the bottom surface, and having a shape tapered at a predetermined angle. Here, the smaller of the two bottom surfaces of the bearing member 151 is referred to as a first surface. Also, the bearing member 151 may be installed at a downward slope with respect to the input shaft 10 . As shown in FIGS. 1 and 2, the first surface of the bearing member 151 faces rearward, and the vertical axis passing through the center of the bearing member 151 gradually moves toward the rear along the input shaft 10 toward the input shaft ( 10) may be provided to have a downward inclination that is inclined to approach. In addition, the first and second inclined surfaces 111a and 141a may be formed to have an inclination with respect to the input shaft 10 , and for example, may be formed to have a downward inclination gradually inclined toward the input shaft 10 toward the rear. Here, the angles of the first and second inclined surfaces 111a and 141a correspond to the taper angle (ie, the angle of the side surface) of the bearing member 151 .

152 in the drawing is a retainer 152 that holds the bearing member 151 .

Meanwhile, unlike the above-described embodiment, an angular ball bearing may be used as the input bearing 150 .

In this case, the input bearing 150 is provided with a ball-shaped bearing member between the internally toothed gear 110 and the housing 140 , similarly to the above-described embodiment, and the inner ring of the input bearing 150 is the internally toothed gear 110 . ) and may be integrally formed, and the outer ring may be integrally formed with the housing 140 . In addition, the internal gear 110 and the housing 140 are formed on inclined surfaces, and the input bearing 150 may be provided with a ball-shaped bearing member on the inclined surface.

According to the present embodiment, since the input bearing 150 is formed of a tapered roller bearing, it can support high radial and axial loads, so it is suitable for supporting the rotation of the wave gear device 100 and, in addition, cross Since it is lightweight compared to the roller bearing, the housing 140 and the wave gear device 100 can be reduced in weight.

As described above, although the embodiments have been described with reference to the limited drawings, those skilled in the art may apply various technical modifications and variations based on the above. For example, the described techniques are performed in a different order than the described method, and/or the described components of the system, structure, apparatus, circuit, etc. are combined or combined in a different form than the described method, or other components Or substituted or substituted by equivalents may achieve an appropriate result.

Therefore, other implementations, other embodiments, and equivalents to the claims are also within the scope of the following claims.

10: input shaft
100: wave gear device
110: internal gear
111: body
111a: first inclined surface
112: internal
120: external gear
121: body
122: shout
123: diaphragm
124: boss
130: wave generator
131: plug
132: bearing
140: housing
141: first housing member
141a: second inclined surface
142: second housing member
150: input bearing
151: bearing member
152: retainer

Claims (6)

input shaft;
a wave generator coupled to the input shaft and having an elliptical cross-sectional shape;
an external toothed gear provided on the outer peripheral surface of the wave generator, the external tooth is formed on the outer peripheral surface of the front end part, and the rear end part extends outwardly to form a boss part;
an internal gear provided on an outer circumferential surface of the externally toothed gear and having internal teeth formed on the inner circumferential surface;
a housing provided outside the internal gear and coupled to the boss; and
an input bearing provided between the internally toothed gear and the housing and including a bearing member formed of a tapered roller;
including,
A first inclined surface corresponding to the taper angle of the bearing member and having a downward inclination toward the rear with respect to the input shaft is formed on the outer peripheral surface of the internal gear, the first inclined surface serving as the inner ring of the input bearing;
a second inclined surface corresponding to the taper angle of the bearing member and inclined downwardly toward the rear with respect to the input shaft is formed on the inner circumferential surface of the housing, the second inclined surface serving as the outer ring of the input bearing;
The bearing member is a wave gear device provided with a first surface facing rearward between the first inclined surface and the second inclined surface.
delete delete delete delete According to claim 1,
The external gear is
a cylindrical body with an open front end; and
a diaphragm in which the other end of the body extends outwardly and the boss is formed;
including,
The internal tooth gear is a wave gear device formed to cover the body.

Images